U.S. patent number 4,260,541 [Application Number 06/076,766] was granted by the patent office on 1981-04-07 for method for producing internally plasticized poly(vinyl chloride).
This patent grant is currently assigned to Ceskoslovenska Akademie Ved. Invention is credited to Miloslav Kolinsky, Vladislav Kuska, Rudolf Lukas, Vendelin Macho, Jaroslav Manas, Juraj Porubsky, Stanislav Sykora.
United States Patent |
4,260,541 |
Kolinsky , et al. |
April 7, 1981 |
Method for producing internally plasticized poly(vinyl
chloride)
Abstract
The invention relates to the method for producing internally
plasticized poly(vinyl chloride) suitable for the purposes of earth
insulation and medical care. The production method according to the
invention consists in the polymerization or copolymerization of
vinyl chloride in an aqueous dispersion medium in the presence of
up to 50 weight %, related to vinyl chloride, of a polymeric
plasticizer prepared by polyesterification of dicarboxylic acids
and diols. If desired, the polymerization can be carried out also
in the presence of up to 12 weight % of alkyl esters of cyanuric
acid and/or the copolymer of ethylene with vinyl acetate as the
stabilizers of polymer-chain structure. The polymerization is
carried out to the conversion of vinyl chloride 55 to 94% at
temperature -20.degree. to +80.degree. C. in the presence of an
emulsifier and the resulting polymer is isolated and worked up in
the known way.
Inventors: |
Kolinsky; Miloslav (Prague,
CS), Macho; Vendelin (Novaky, CS),
Porubsky; Juraj (Bratislava, CS), Kuska;
Vladislav (Novaky, CS), Manas; Jaroslav
(Gottwaldov, CS), Sykora; Stanislav (Gottwaldov,
CS), Lukas; Rudolf (Prague, CS) |
Assignee: |
Ceskoslovenska Akademie Ved
(Prague, CS)
|
Family
ID: |
9230344 |
Appl.
No.: |
06/076,766 |
Filed: |
September 18, 1979 |
Current U.S.
Class: |
524/101; 524/567;
525/11; 525/167; 525/170; 525/27 |
Current CPC
Class: |
A61L
29/049 (20130101); A61L 29/141 (20130101); C08F
14/06 (20130101); C08F 255/026 (20130101); C08F
283/02 (20130101); C08G 81/027 (20130101); C09K
17/52 (20130101); C08F 14/06 (20130101); C08F
2/16 (20130101); C08F 255/026 (20130101); C08F
214/06 (20130101); C08F 283/02 (20130101); C08F
214/06 (20130101); A61L 29/049 (20130101); C08L
67/00 (20130101) |
Current International
Class: |
A61L
29/04 (20060101); A61L 29/00 (20060101); A61L
29/14 (20060101); A01G 13/02 (20060101); C08F
14/00 (20060101); C08F 14/06 (20060101); C08F
255/00 (20060101); C08F 283/00 (20060101); C08F
255/02 (20060101); C08F 283/02 (20060101); C08G
81/02 (20060101); C08G 81/00 (20060101); C08L
067/02 () |
Field of
Search: |
;525/11,167,27,170
;260/29.2UA,29.2N,29.2E,29.6NR,45.8NT,45.85R,16,17A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ziegler; J.
Claims
We claim:
1. A method for producing internally plasticized
poly(vinylchloride) which is suitable primarily for the purposes of
earth insulation and medical care, wherein vinyl chloride is
polymerized in an aqueous dispersion medium in the presence of up
to 50 weight % based on vinyl chloride of a polyester polymeric
plasticizer, which is prepared by polyesterification of
dicarboxylic acids selected from the group consisting of adipic and
sebacic acid and diols having 2 to 8 carbon atoms in the molecule
selected from the group comprising ethylene glycol, diethylene
glycol, 1,2-propandiol and 1,4-butandiol in the presence up to 5
wt.% of a stabilizer of the polymer chain structure, to effect a
50-90% conversion of the vinyl chloride at temperatures from
-20.degree. to +80.degree. C. and a pressure up to 1 MPa; and
wherein the resulting polymer is isolated.
2. The method according to claim 1, wherein said stabilizer is
triallylcyanurate.
3. The method according to claim 1, wherein said stabilizer is an
ethylene-vinyl acetate copolymer containing from 30 to 45 wt.% of
vinyl acetate.
Description
The invention pertains to the method for producing internally
plasticized poly(vinyl chloride), particularly suitable for the
purpose of earth insulations, using the common polymerization
equipment.
It is know that poly(vinyl chloride) cannot be processed in a pure
form, but only with various auxiliary compounds added, as
plasticizers, heat and light stabilizers, lubricants, pigments,
fillers, and the like. These additives enable the processing and
render the desired properties required for a final article. The
addition of plasticizers provides the material with flexibility,
workability, thermoplasticity, increases the internal mobility of
macromolecules, etc. The applied plasticizers are low-volatile
liquid or solid organic compounds, e.g. the high-boiling esters of
phthalic, sebacic, adipic, and phosphoric acids.
It appears that poly(vinyl chloride) plasticized in this way turns
hard and brittle and loses the weight after some time due to the
loss of plasticizer. This loss may be caused by the volatility of
plasticizer, unsuitable atmospheric conditions, extraction with
water or other liquids which dissolve the plasticizer or react with
it, or by the migration of plasticizer in the contact with other
materials.
It is very difficult to preclude this deterioration process. Some
improvement was achieved by the application of high-molecular
weight compounds with the plasticizing effect, so called polymeric
plasticizers, e.g. polyester plasticizers or plasticizing polymers
or copolymers, as a styrene-acrylonitrile copolymer,
polyisobutylene, poly(vinyl ethers), and the like.
The both cases represent the external plasticizing and the
respective plasticizer and other auxiliary compounds have to be
introduced into poly(vinyl chloride) in such way, that the
resulting plasticized poly(vinyl chloride) is perfectly
homogeneous. The plasticizer is mechanically worked into powdered
poly(vinyl chloride). It is therefore very difficult and laborious
to prepare the perfectly homogeneous blend and a relatively long
mixing, gelation and exposure to a high processing temperature are
necessary. In addition, the external plasticizing is not quite
satisfactory because the plasticizer tends to migrate to the
surface and is evaporated or extracted eventually.
Substantial improvement was attained by so called internal
plasticizing when a plasticizer or a similar compound is
incorporated by polymerization into the chain of poly(vinyl
chloride) and became its part. If the low-molecular weight
plasticizers are used for this purpose, the desired improvement
does not occur because low-molecular weight compounds act as
effective chain transfer agents in the polymerization giving rise
to the low-molecular weight polymer--the oligomeric product with
wrong rheological properties which is useless for practice.
Czechoslovak Patent No. 140,523 claims the manufacturing of
internally plasticized poly(vinyl chloride) by block polymerization
carried out up to the conversion of 35 to 55%. Low yields and the
difficult removal of polymerization heat are the main disadvantage.
This polymer is designated exclusively for application as a damping
material for electroacoustic purposes.
They are also know copolymers of vinyl chloride with acrylates
(U.S. Pat. No. 3,544,661), but they form heterogeneous resin
mixtures which do not have the required processing properties. The
aim is the production of internally plasticized poly(vinyl
chloride) suitable for the preparation of stable flexible foils for
earth insulations where the long service life 50 to 70 years is
required. The material should not lose its original properties in
time, should not liberate the plasticizing components, should not
undergo degradation, destruction and other processes under the
effect of soil humidity and of the respective corossive compounds
in underground water, or changes by temperature in the region
-50.degree. to +50.degree. C., and has to be well processable.
The method for producing internally plasticized poly(vinyl
chloride) suitable above all for the purpose of earth insulations
and medical care consists according to this invention in the
polymerization and/or copolymerization of vinyl chloride which is
carried out in an aqueous dispersion medium, preferably in emulsion
and/or suspension, in the presence of the polyester polymeric
plasticizer prepared by polyesterification of dicarboxylic acids
having 4 to 16 carbon atoms, preferably 6 to 12 carbon atoms, in
the molecule and diols having 2 to 8 carbon atoms in the molecule,
advantageously ethylene glycol, diethylene glycol, and
1,4-butanediol, in the amount up to 50 wt.% related to vinyl
chloride, and if desired, also in the presence of alkyl esters of
cyanuric acid, preferably of diallyl cyanurate and/or triallyl
cyanurate, and/or in the presence of the ethylene-vinyl acetate
copolymer, which contains 10 to 50 wt.% advantageously 30 to 45
wt.%, of vinyl acetate incorporated into the copolymer, as the
stabilizer of polymer-chain structure in the amount up to 12 wt.%,
preferably up to 5 wt.%, to the conversion of vinyl chloride 55 to
94 %, advantageously 70 to 90%, at the temperature -20.degree. to
+80.degree. C. and the pressure corresponding to the respective
temperature, and in the isolation and processing of the resulting
polymer in the known way.
Polyesters of adipic, sebacic, and phthalic acid and glycols
containing 2 to 8 carbon atoms in the molecule, preferably ethylene
glycol or butylene glycol individually or in mixtures, or in
combinations with other compounds, e.g. diols, advantageously with
1,2-propanediol, 1,3-butanediol, and 1,4-butanediol, are
advantageously employed as the compounds which are able to be
incorporated into the chains of poly(vinyl chloride) formed or to
be bonded to these chains. These compounds are advantageously added
in the amount up to about 50 wt.%. The polymeric compound of the
molecular weight ranging from 2500 to 7000 is preferably used. To
improve the mechanical properties while keeping the sufficient
elasticity, a certain small amount of such organic compound is
added to the polymerization mixture which is also incorporated into
the polymer and act in the system as a "stabilizer" of polymer
structure. Organic compounds with functional groups able to react
with poly(vinyl chloride) chains are advantageously used for this
purpose, as diallyl or triallyl cyanurate, or various copolymers
which can be grafted on chains, as e.g. the copolymer of ethylene
with vinyl acetate, in the amount up to 12 wt.%, advantageously up
to 3 wt.%.
On the one hand, the polymeric plasticizers are perfectly
distributed in the suspension particles of polymer since the moment
of their formation, on the other, they are bonded to the free
radicals of macromolecular chains of poly(vinyl chloride) above all
by combination with radicals easily formed in the macromolecules of
polyester at the .alpha.-position to ester groups. At the same
time, only one chemical bond between the poly(vinyl chloride)
macromolecule and, for example, the polyester macromolecule is
entirely sufficient.
To achieve the perfect dispersion of vinyl chloride, comonomers,
modifiers, and polymeric plasticizers in the polymerization (or
also grafting) medium, common dispersing agents are used, as
cellulose ethers, particularly methylhydroxypropyl cellulose,
hydroxyethyl cellulose, methyl cellulose, and the like, partially
hydrolyzed poly(vinyl acetate) or poly(vinyl alcohol), partially
esterified multifunctional alcohols, partially saponified fats,
etc., and sometimes also the products of emulsifiers, as sodium
dodecylsulfate, sodium salts of sulfonated alkanes,
sulfosuccinazes, and others.
EXAMPLES 1 TO 8
A glass pressure reactor of volume 1 dm.sup.3, which was equipped
with a duplicating jacket, a horseshoe stirrer with revolution
control, and a pressure gauge, was charged with the polymeric
plasticizer. The type and amount of plasticizer calculated on the
expected amount of formed polymer are given in Table I. Then, the
aqueous phase was added which contained 10.2 cm.sup.3 of the water
solution of methylhydroxypropyl cellulose of concentration 2.5 wt.%
as a dispergator, 1 cm.sup.3 of sodium hydroxide solution of
concentration 1 wt.% as a "buffer", and 390 cm.sup.3 of distilled
water. Dilauroyl peroxide (0.15 g) and diisopropyl peroxocarbonate
Perkadox 16 (0.029 g) were further added.
The reactor was closed, flushed with a small amount of vinyl
chloride to remove air and 100 g of vinyl chloride was let in under
stirring (300 r.p.m.).
The content of reactor was rapidly heated to the polymerization
temperature 51.degree. C. rising the pressure to 0.74 MPa
consequently. The polymerization was carried out at 51.degree. C.
under continuous stirring from 350 to 650 r.p.m. in such way, that
the components were kept in suspension, as long as the pressure
dropped from 0.74 MPa to 0.6 MPa. The total polymerization period
ranged from 7.5 to 11 hours at this temperature, according to the
amount and the type of polymeric plasticizer.
After the polymerization was finished, the content of reactor was
rapidly cooled and the resulting product was threetimes decanted
with warm distilled water, isolated by filtration, and dried at
25.degree. C.
The examples 1 to 8 were carried out according to this procedure.
Their results are shown in Table I.
EXAMPLES 9 TO 13
A stainless-steel autoclave of volume 8 dm.sup.3, which was
equipped with a duplicating jacket, a propeller agitator, breaking
partitions at the inner wall of reactor, and a pressure gauge, was
charged with the polymeric plasticizer. Its type and amount
(calculated on the expected amount of resulting polymer) are given
in Table I.
The aqueous phase was then added which consisted of 147.6 g of 2.5
wt.% water solution of methylhydroxypropyl cellulose as a
dispersion agent, 6 dm.sup.3 of 1.2 wt.% NaOH solution as a buffer
agent, and 4000 g of distilled water.
Dilauroyl peroxide (2.2 g) and diisopropyl peroxocarbonate Perkadox
16 (0.3 g) were then added.
The reactor was flushed with a small amount of vinyl chloride to
remove air, 1000 g of vinyl chloride was let in under stirring (150
r.p.m.), and the reactor was heated to 59.5.degree. C. causing the
pressure increase to 0.91 MPa.
TABLE I
__________________________________________________________________________
Polymeric Polymerization Polymerization Type of polymeric
plasticizer Example temperature time plasticizer Added Content in
Conversion K no. (.degree.C.) (h) (polyester) (g) product (%) (g)
(%) value
__________________________________________________________________________
1 51 8,00 Adipic acid + 15 21,74 69 69 55,9 2 51 7,45 ethylene
glycol 20 27,39 73 73 52,6 3 51 8,00 Adipic acid + 17,5 20,58 85 85
64,5 4 51 7,45 1,2-propanediol 23 25,84 89 89 61,3 5 51 11,00
Adipic acid + 15 17,44 86 86 62,5 6 51 7,30 1,4-butanediol 20 22,22
90 90 60,1 7 51 8,00 Sebacic acid + 15 22,72 66 66 58,7 8 51 8,30
1,4-butanediol 20 22,72 88 88 58,7 9 59,5 6,30 Adipic acid + 152
16,6 895 72,0 51,6 10 59,5 6,15 ethylene glycol 240 20,6 1165 79,5
53,1 11 59,5 4,00 Adipic acid + 150 17,6 850 69,3 51,3 12 59,5 4,30
1,4-butanediol 240 21,2 1130 78,8 55,7 13 59,5 4,15 Sebacic acid +
180 15,7 1143 79,3 58,0 1,4-butanediol
__________________________________________________________________________
The polymerization mixture was maintained at temperature
59.5.degree. C. under stirring at 150 r.p.m. as long as the
pressure decreased from 0.91 MPa to 0.7 MPa. The total
polymerization period was 8 hours.
After the polymerization was completed, the content of the reactor
was rapidly cooled and the resulting polymer was three-times
decanted with warm distilled water, filtred, and dried at
temperature 25.degree. to 30.degree. C.
The examples 9 to 13 were carried out according to this procedure
and their results are in Table I. Some basic properties of the
samples of internally plasticized poly(vinyl chloride) prepared in
this way are given in Table IIa and IIb.
The following physico-chemical characteristics were determined with
the samples of internally plasticized poly(vinyl chloride) prepared
according to Examples 9 to 13:
TABLE IIa ______________________________________ Sample according
to Example no. Characteristics Unit 9 10 11 12 13
______________________________________ Bulk weight g.dm.sup.-3
611,9 662,8 586,2 600,0 577,7 Screen analysis 350 .mu.m % 21,32
28,8 0,36 0,2 0,4 250 .mu.m % 37,54 50,9 0,92 0,48 0,52 63 .mu.m %
70,52 78,6 78,44 83,52 89,8 Absorption of plasticizer min 5 7 4 4 4
Thermal stabi- lity at 180.degree. C. min 120 120 85 75 120
______________________________________
The samples of internally plasticized poly(vinyl chloride), which
were prepared according to Examples 9 to 13, were further tested in
two series:
(A) In blends without pigments
(B) In blends filled with carbon black
Ad(A) The blends were prepared according to the following
formula:
______________________________________ Internally plasticized
poly(vinyl chloride) 200 wt. parts (samples 9 to 13) Advastab BC 26
4 wt. parts Dioctyl adipate 40 wt. parts Irgastab CH 300 1,5 wt.
parts Wax E 1,5 wt. parts Stearin 0,5 wt. parts
______________________________________
Each blend of the given composition was homogenized in a two-roll
mill (350.times.600 mm) at temperature 162.degree. to 165.degree.
C. for 8 min. The rails of thickness 0.6 mm were used for the
determinations of thermal stability which is presented in Table
IIb.
TABLE IIb ______________________________________ Sample according
to Example No. Characteristics Unit 9 10 11 12 13
______________________________________ Thermal stability at
180.degree. C. min 120 120 85 75 120
______________________________________
Another part of the foils was repressed in a multistage press at
170.degree. C. to foils of thickness 1 mm. These foils were used
for measuring of physico-mechanical characteristics. The results
are given in Table IIc.
TABLE IIc ______________________________________ Sample according
to Example no. Characteristics Unit 9 10 11 12 13
______________________________________ Tensile strength MPa 16,2
14,2 15,6 13,8 17,6 Breaking elongation % 401 383 385 421 424 Tear
resistance N/mm 17,8 11,8 16,0 11,1 16,7 Hardness Shore A
.degree.Sh 85 82 83 79 86 Shore B .degree.Sh 32 28 30 26 33
Internal elec. resistivity Ohm -- -- -- -- --
______________________________________
The tensile strength as well as the Shore hardness correspond to
the content of incorporated polymeric plasticizer. Samples 9, 10
and 13 exhibit the substantially higher thermal stability than
samples 11 and 12.
Ad(B) The second series of testing was carried out with blends
filled with carbon black (8% Ketjenblack EC) where the content of
dioctyl adipate was adepted with respect to the various content of
grafted polymeric plasticizer.
The following results given in Table IId were obtained by measuring
the characteristics of repressed foils:
TABLE IId ______________________________________ Sample according
to Example no. Characteristics Unit 9 10 11 12 13
______________________________________ Tensile strength Mpa 12,2
12,4 11,6 12,0 12,5 Breaking elongation % 202 172 238 188 228 Tear
resistance N/mm 7,64 8,10 7,45 7,64 8,14 Hardness Shore A
.degree.Sh 88 90 89 86 91 Shore B .degree.Sh 40 41 37 38 39
Internal. elec. resistivity Ohm 1.10.sup.4 1.10.sup.4 3.10.sup.4
2.10.sup.4 4.10.sup.4 ______________________________________
EXAMPLES 14 TO 17
The procedure was the same as in Examples 9 to 13 with the
distinction that 1000 g of vinyl chloride was polymerized at
48.degree. C. as long as the initial pressure 0.71 MPa decreased to
0.60 MPa. The results obtained in Examples 14 to 17 are shown in
Table IIIa.
The samples of internally plasticized poly(vinyl chloride)
according to Examples 16 and 17 were characterized by their
physico-chemical properties both pigmented and without pigment.
The blends without pigments were prepared according to the formula
used in Example 9 to 13. Also the foils for measuring the
physico-chemical properties were prepared in the same way as in
Examples 9 to 13.
TABLE III
__________________________________________________________________________
Polymeric Polymerization Polymerization Type of polymeric
plasticizer Example temperature time plastizier Added Content in
Conversion K no. (.degree.C.) (h) (polyester) (g) product (%) (g)
(%) value
__________________________________________________________________________
14 48,0 8 150 24,1 621 47,1 62,9 15 48,0 8 Adipic acid + 200 29,7
715 51,5 60,9 ethylene glycol 16 48,0 8 83 14,1 592 50,9 65,6 17
48,0 8 117 18,9 617 50,0 64,6
__________________________________________________________________________
About 11% of carbon black (Ketjenblack EC) was added into pigmented
blends. The obtained results are presented in Table IIIb.
TABLE IIIb ______________________________________ Sample according
to Example no. Without pigments Pigmented Characteristics Unit 16
17 16 17 ______________________________________ Tensile strength
Mpa 26,6 23,9 19,8 19,1 Breaking elongation % 418 490 332 304 Tear
resistance N/mm 21,8 21,5 9,42 9,58 Hardness Shore A .degree.Sh 90
86 91 92 Shore B .degree.Sh 38 32 43 44 Internal elec. resistivity
Ohm -- -- -- -- Frost resistance NHSP .degree.C. -31 -30 -11 -6
______________________________________
EXAMPLES 18 TO 20
A 2 dm.sup.3 stainless-steel autoclave equipped with a duplicating
jacket and a horseshoe stirrer (300 r.p.m.) was charged with 810 g
of distilled water, 90 g of the 2 wt.% water solution of
methylhydroxypropyl cellulose, 0.8 g of trichloroethylene, 0.04 g
of sodium hydroxide, 1.4 g of dilauroyl peroxide, and 0.2 g of
di(tert-butylcyclohexyl) peroxocarbonate. Polyesterpolyol prepared
by polyesterification of adipic acid with ethylene glycol and
1,4-butanediol and having the following physicochemical properties:
density at 20.degree. C. 1.18 g.cm.sup.-3, at 30.degree. C. 1.16
g.cm.sup.-3, and at 50.degree. C. 1.15 g.cm.sup.-3, dynamic
viscosity at 20.degree. C. 28.531 Pa.s (28931 cP), at 30.degree. C.
13.018 Pa.s. (13018 cP) and at 50.degree. C. 3.93 Pa.s (3930 cP),
average molecular weight 3676, acid no. 1.6 mg KOH/g; hydroxyl no.
42.9 mg KOH/g; water content 0.035 wt.%, was then added under
continuous stirring in the amount of 210 g.
Air was removed, 700 g of vinyl chloride was let in, and the
temperature was raised to 56.degree. C. The pressure in autoclave
reached 1 MPa after attaining this temperature. The polymerization
was carried out at the given temperature for 6 hours and the
pressure dropped during this time to 0.6 MPa.
The content of autoclave was then rapidly cooled and quantitatively
discharged. The suspension polymer was filtered, threetimes washed
on filter with warm water, and dried at temperature 50.degree.
C.
The Examples 18 to 20 were carried out according to this procedure.
The results are shown in Table IVa; some basic characteristics of
the prepared samples of internally plasticized poly(vinyl chloride)
are given in Tables IVb and IVc.
Some basic characteristics of the samples of internally plasticized
poly(vinyl chloride) which were prepared according to the procedure
described for Examples 18 to 20:
TABLE IVa
__________________________________________________________________________
Polymeric Polymerization Polymerization Type of polymeric
plasticizer Example temperature time plasticizer Added Content in
Conversion K no. (.degree.C.) (h) (polyester) (g) product (%) (g)
(%) value
__________________________________________________________________________
18 56 6 Adipic acid + 210 29,9 703 70,4 50,5 19 56 7 ethylene
glycol 175 24,6 710 76,0 52,5 20 56 7 Adipic acid + 150 21,2 709
79,8 53,8 1,4-butanediol
__________________________________________________________________________
10 g of powdered poly(vinyl chloride) of each sample 18 to 20 was
extracted with 100 g of boiling methanol for 3 hours. The extracted
amounts were:
______________________________________ Sample 18 8.2 wt. % of
polyesterpolyol polymeric plasticizer Sample 19 7.4 wt. % of
polyesterpolyol polymeric plasticizer Sample 20 6.8 wt. % of
polyesterpolyol polymeric plasticizer
______________________________________
The following physicochemical properties given in Table IVb were
determined with the samples of internally plasticized poly(vinyl
chloride) prepared according to Example 18 to 20.
TABLE IVb ______________________________________ Sample according
to Example no. (unextracted) Characteristics Unit 18 19 20
______________________________________ Bulk weight g.dm.sup.-3 654
731 610 Screen analysis 250 .mu.m % 8,2 1,2 60,6 100 .mu.m % 8,2
25,4 24,2 63 .mu.m % 73,6 74,4 15,2 Absorption of plasticizer min 3
10 4 ______________________________________
Both unextracted and extracted samples of the suspension internally
plasticized poly(vinyl chloride) were used for preparation of soft
foils with 1.5 wt.% of basic lead stearate added as a heat
stabilizer and 0.5 wt.% of wax as an external lubricant, by
calendering at temperature 150.degree. C. for 5 min. Table IVc
shows the thermal stabilities of samples prepared according to
Examples 18 to 20.
TABLE IVc ______________________________________ Sample according
to Example no. Characteristics Unit 18 18E 19 19E 20 20E
______________________________________ Thermal stability at
150.degree. C. min 94 94 95 96 98 102
______________________________________ Note: E means the sample
extracted with methanol.
EXAMPLES 21 TO 24
A glass pressure reactor of volume 1 dm.sup.3, which was equipped
with a duplicating jacket, a horseshoe stirrer with revolution
control, and a pressure gauge, was charged with the polymeric
plasticizer and a crosslinking agent, the type and amount of which
are given in Table V. Then the aqueous phase was added which
contained 18 cm.sup.3 of 2.5 wt.% water solution of
methylhydroxypropyl cellulose as a dispersion agent, 1.9 cm.sup.3
of 5.1 wt.% solution of sodium hydroxide as a "buffer" and 350
cm.sup.3 of distilled water. Dilauryl peroxide (0.25 g) and
diisopropyl peroxocarbonate (0.08 g) were further added.
The reactor was closed, flushed with a small amount of vinyl
chloride to remove air, and 180 g of vinyl chloride was let in
under stirring (300 r.p.m.).
The content of reactor was rapidly heated to the polymerization
temperature 51.degree. C. and the pressure increased to 0.76 MPa
consequently. The polymerization was carried out at 51.degree. C.
under continuous stirring at 350 to 650 r.p.m., to keep the
components in suspension, as long as the pressure dropped from 0.76
MPa to 0.61 MPa. The total polymerization time ranged from 6.5 to
8.5 h with respect to the amount and the type of added polymeric
plasticizer and crosslinking agent.
After the polymerization was finished, the reactor content was
rapidly cooled and the resulting product was threetimes decanted
with warm distilled water, filtered, and dried at 25.degree. C.
Examples 21 to 24 were carried out according to the above procedure
and their results are shown in Table V.
Internally plasticized poly(vinyl chloride) prepared in this way is
particularly suitable for manufacturing of earth-insulating
flexible foils of long service life and for the purposes of medical
care (bags for blood and infusion solutions, catheters, transfusion
sets, and the like).
TABLE V
__________________________________________________________________________
Polymerization Polymerization Polymeric stabilizer/Stabilizing
agent Example temperature time Added Content in Conversion K no.
(.degree.C.) (h) Components (g/%) product (%) (g) (%) value
__________________________________________________________________________
21 51 8,0 Adipic acid + 1,4-butanediol 20/1 14,8/0,7 155 75,0 66,3
22 51 8,5 Adipic acid + 30/1,5 23,4/1,2 158 71,2 -- 1,4-butanediol
+ triallyl cyanurate 23 51 6,5 Adipic acid + 40/3 32/2,4 165 69,4
62,2 1,4-butanediol 24 51 7,0 Adipic acid + 35/2 26,9/1,5 167 72,2
59,3 1,4-butanediol + copolymer ethylene/vinyl acetate
__________________________________________________________________________
* * * * *